Yotan Ottolenghi's Shrimp Bolognese

Name: Yotan Ottolenghi's Shrimp Bolognese
Prep time: 10 min
Cook time: 30 min
Total time: 40 min
Cuisine: European, Italian, Mediterranean
Ingredients: ½ small fennel bulb, roughly chopped; ½ small onion, roughly chopped; 5 garlic cloves, roughly chopped; ½ teaspoon red-chile flakes; 1 ⅓ pounds/600 grams peeled, raw king prawns or extra-jumbo shrimp (or use the largest shrimp you can find); ⅓ cup plus 1 tablespoon/90 milliliters olive oil; 1 lemon, finely shaved to get 5 strips of peel and squeezed to get 1 tablespoon juice; 3 tarragon sprigs (about 5 grams), plus 1 tablespoon chopped leaves for serving. Note: I omitted this entirely and decorated the top of the dish with finely chopped chives; 3 ½ tablespoons tomato paste; ¼ pound/120 grams cherry tomatoes, finely chopped; Salt and black pepper; ⅓ cup plus 1 tablespoon/90 milliliters Pernod (or a similar anise liqueur); 2 cups/500 milliliters chicken or vegetable stock; 12 ounces/320 grams dried tagliatelle pasta